在Linux上安装MySQL

1、准备环境：安装一个MySQL数据库
数据库的连接池 ----> 返回的Connection，不是真正的Connection，而是一个代理对象
准备环境：安装一个MySQL数据库

			在虚拟机上安装MySQL：
			yum remove mysql-libs 
			rpm -ivh mysql-community-common-5.7.19-1.el7.x86_64.rpm
			rpm -ivh mysql-community-libs-5.7.19-1.el7.x86_64.rpm
			rpm -ivh mysql-community-client-5.7.19-1.el7.x86_64.rpm
			rpm -ivh mysql-community-server-5.7.19-1.el7.x86_64.rpm
			rpm -ivh mysql-community-devel-5.7.19-1.el7.x86_64.rpm  （可选）
						
				启动MySQL：service mysqld start
				或者：systemctl start mysqld.service

				查看root用户的密码：cat /var/log/mysqld.log | grep password
				登录后修改密码：alter user 'root'@'localhost' identified by 'Welcome_1';

			MySQL数据库的配置：
			创建一个新的数据库：create database hive;
			创建一个新的用户：
			  create user 'hiveowner'@'%' identified by 'Welcome_1';
			  
			给该用户授权
			   grant all on hive.* TO 'hiveowner'@'%'; 
			   grant all on hive.* TO 'hiveowner'@'localhost' identified by 'Welcome_1';